Biomedical subjects

R B Keyser

Publications and source records attributed to R B Keyser.

8 recordsLinked to original sources

PubMed1997

Infectious posterior scleritis caused by Pseudallescheria boydii. Clinicopathologic findings.

PURPOSE: The purpose of the study is to describe an unusual case of infectious posterior scleritis after excision of a pterygium. METHODS: The case history of a patient in whom anterior and posterior scleritis developed after excision of a pterygium is reviewed. Histopathologic findings are presented. RESULTS: Pathologic examination results of a scleral biopsy site and the eye showed extensive involvement of the posterior sclera with fungi that on culture grew Pseudallescheria boydii. The development of posterior scleral thickening and intrascleral abscesses gave the clinical impression of autoimmune posterior scleritis or possible tumor. Ultrasonography and computed tomography scan of the eye and orbit proved particularly helpful in following progression of scleral involvement. CONCLUSIONS: Pseudallescheria boydii is capable of causing an infectious posterior scleritis, which can mimic autoimmune posterior scleritis. The use of systemic immunosuppressive agents contributed to this unusual clinical presentation. Progression of posterior scleritis in the face of apparent adequate immunosuppressive therapy always should suggest the possibility of tumor or infection.

Aged↗

PubMed1996

Aggressive conjunctival squamous cell carcinoma in three young Africans.

Polymerase chain reaction was used to test for the presence of human papillomavirus in conjunctival squamous cell carcinomas from three young Africans with aggressive disease. Two of these patients had the acquired immunodeficiency syndrome. Test results for human papillomavirus were negative [corrected] in all three cases.

Acquired Immunodeficiency Syndrome↗

PubMed1986

Cell body counts in human ciliary ganglia.

Baseline cell body counts were performed on 32 human ciliary ganglia obtained during 16 consecutive autopsies. The mean age of the individuals was 53.4 yr, with a range of 17-97 yr. The cell body counts ranged from 1088-6835 cell bodies per ganglion. The mean cell body count was 2473 for specimens from the right side, 2316 for the specimens from the left side, and 2394 for the combined sides. The mean counts in men were 2837 for the right sides, 2533 for the left sides, and 2685 for both sides. The mean counts in women were 2004 for the right sides, 2036 for the left sides, and 2020 for the combined sides. The decreased number of cell bodies in women compared to the population mean was not statistically significant. There was no correlation between age and cell body counts. There was also no statistically significant difference of the cell body counts from individuals with systemic hypertension, myocardial infarction, or cancer and the population mean.

Adie Syndrome↗

PubMed1985

Characterization of limestones and their effects in vitro and in vivo in dairy cattle.

Capacities of limestones of differing particle size to neutralize acid in vitro and to modify pH and utilization of feedstuffs in vivo were compared. Acid neutralization during pH-stat titrations was faster for fine than for coarse limestone, and mixed microbial cultures were more resistant to pH change when they contained fine calcium carbonate. Diets containing 25:75 corn silage to concentrates and .95% calcium from either coarse or fine limestone were fed to rumen-fistulated heifers. Total ruminal volatile fatty acid concentrations were higher for the fine limestone treatment. Ruminal volumes, dry matter disappearance, and ruminal fluid pH and dilution rate did not differ between fine and coarse limestone treatments. Ruminal fluid volume, osmolality, ratios of acetate to propionate, and concentrations of total volatile fatty acids were unaffected in rumen-fistulated Holstein cows fed 60:40 corn silage to concentrates and either .5% calcium (control) or 1.0% calcium from either coarse or fine limestone. Ruminal pH increased .07 to .10 units with limestone supplementation. Ruminal fluid dilution and particulate turnover rates were slower for the coarse limestone than the control treatment. Differences between coarse and fine limestones in vitro were observed under some conditions in vivo, but they were not consistent.

Animal Feed↗

PubMed1982

Neutralization of acid in the rumen by magnesium oxide and magnesium carbonate.

Two reagent and two feed grade magnesium oxides and reagent grade magnesium carbonate, sodium bicarbonate, and calcium carbonate were evaluated to ascertain their ability to neutralize acid in the rumen. Rumen fluid pH was increased in vitro, compared to the control, by antacid compounds, and their increased ranked: calcium carbonate less than feed grade magnesium oxide A less than light magnesium oxide and feed grade magnesium oxide B less than heavy magnesium oxide less than magnesium carbonate less than sodium bicarbonate. Titrations at constant pH's ranging from 3.0 to 7.5 indicated that these magnesium compounds were reactive at pH's normally in the rumen although reactivity decreased with increasing pH. Intraruminal doses of feed grade magnesium oxide A and calcium carbonate did not change rumen fluid pH for other compounds ranked: feed grade magnesium oxide B less than magnesium carbonate less than heavy magnesium oxide. Feeding of heavy magnesium oxide or magnesium carbonate increased rumen fluid pH as compared to the control diet. Feeding feed grade magnesium oxide B in three quantities to cattle resulted in proportional increased in fecal pH and fluidity of feces. Two feed grade magnesium oxides differed in their ability to neutralize acid in the rumen.

Animals↗

PubMed1980

Comparison of the pattern and diffuse-light visual evoked responses in definite multiple sclerosis.

We prospectively studied 100 patients with "definite" multiple sclerosis to determine which of three methods of stimulation most consistently had results that disclosed abnormalities in the visual evoked response when they were compared with those from normal controls. The three methods were diffuse flashes of light, intermittent reversing pattern, and constant luminous but reversing pattern. The most sensitive indicator of abnormality of the visual evoked response was the latency of the major occipital positive peak. Virtually no difference was evident between the results from the two methods of pattern stimulation. Of only slightly less sensitivity was the latency of the major positive peak with diffuse-light stimulation, and this showed a prolonged latency in a greater number of patients when visual acuity was poor. Abnormalities of latency of the first negative peak and of amplitude were not related to the clinical expression of the multiple sclerosis, whether relapsing, progressive, or relapsing and progressive.

Adult↗

PubMed1980

Influence of dietary calcium and protein on fecal pH, consistency, and rate of passage in dairy cattle.

Sixteen Holstein heifers and 20 calves were in trials on the effect of 10 and 15% crude protein and .3 and .9% calcium in the diet on fecal pH and consistency and on rate of passage of the liquid phase of digesta. Time of first appearance of polyethylene glycol was an indicator of rate of passage of the liquid phase in the lower tract of the animal. Respective fecal pH and standard errors for heifers and calves increased from 5.79 +/- .03 and 5.78 +/- .03 on low calcium diets to 6.24 +/- .03 and 6.33 +/- .03 on high calcium diets. High protein diets increased fecal pH from 5.89 +/- .03 and 5.97 +/- .03 to 6.13 +/- .03 and 6.14 +/- .03 for heifers and calves. Effects of calcium and protein were additive. Neither dietary protein nor calcium affected consistency of feces or first appearance of polyethylene glycol in feces. Mean first appearances of PEG in feces were 683 +/- 13 min for heifers and 528 +/- 18 min for calves. Small correlations between fecal pH and fecal consistency and between fecal pH and first appearance of polyethylene glycol in feces indicate little or no relationship of fecal pH to these two variables. From variance in the heifer trial, 10 fecal samples are required to estimate fecal pH within +/-.16 pH units with 95% confidence.

Animals↗

PubMed1978

Iridocyclectomy for melanomas of the ciliary body: a follow-up study of pathology and surgical morbidity.

With respect to the effect of surgical treatment upon the eye and the subsequent tumor behavior, 107 cases of ciliary body melanoma treated by iridocyclectomy were studied. Surgically induced complications are discussed; 6% of the patients operated on culminated in enucleation, and 42% of the patients had a final postoperative visual acuity of 20/40 or better. Pathologically, most of the cases were spindle cell A or B; a few were mixed or epithelioid type. Histologic evidence of incomplete excision did not regularly predict recurrence in the interval of observation. Cell type is the primary prognostic feature. Local complications such as recurrence of tumor, or the rare metastasis occur early.

Cataract↗